Transmission for driving the screws of a twin-screw extruder

Abstract

A transmission for driving the screws of a twin-screw extruder comprises two parallel output shafts ( 1, 2 ) of different lengths and rotating in opposite directions, the shorter one of which carries a drive gear ( 4 ) meshing with one gearwheel ( 6 ) each of two distributor shafts ( 7 ), which from the side of the longer output shaft ( 1 ) can be driven by an intermediate shaft ( 10 ) via gearwheels ( 11 ). To create advantageous constructional conditions it is proposed that on the longer output shaft ( 1 ) a gearwheel ( 5 ) meshing with the drive gear ( 4 ) of the shorter output shaft ( 2 ) is affixted.

What is claimed is:  
     
       1. A transmission for driving the screws of a twin-screw extruder comprising a shorter output shaft, a longer output shaft, the output shafts extending parallel to each other and rotating in opposite directions, and a tandem bearing for the shorter output shaft, which transmission increases the transmittable torque without interfering with the tandem bearing for the shorter output shaft and comprises 
       (a) two distributor shafts,  
       (1) each distributor shaft carrying a gearwheel,  
       (b) a drive gear on the shorter output shaft, the drive gear meshing with the gearwheels,  
       (c) a gearwheel on the longer output shaft, said gearwheel meshing with the drive gear,  
       (d) an intermediate shaft for driving the distributor shafts,  
       (1) the intermediate shaft carrying a gearwheel meshing with an additional gearwheel on the longer output shaft.  
     
     
       2. The transmission of claim  1 , comprising a further distributor shaft for driving the drive gear on the shorter output shaft. 
     
     
       3. The transmission of claim  1 , wherein the output shafts are disposed in a common parting plane of a transmission casing.